Airplane towing means



Filed `OCt. 27, 1942 2 Sheets-Sheet l J. c. BElRlsE AIRPLANE TOWINGMEANS Filed Oct.

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veA/ls /5 Patented June 13, 1944 UNITED STATES PATENT OFFICE 2,350,999 ymmm: 'rowlNG MEANS John C. Denise. Dayton, Ohio l.lipplieatnm october21. 1942, serial No. 463,556V 4 claims. (ci. aimais) (Granted yman then: af March a, 1883, as amended yapril 3o, 192s; 37o o. G. '151) 'I'heinvention described herein may bemannfactured and Aused by or forGovernment for governmentalpurposes, without lthe payment to me vof anyroyalty thereon.

This invention relates to towing means adapted particularly for use inairplane and glider towing operations. f

For such purposesit is desirable that thetowing connection between thevairplane and the glider be releasable at will to enable the vairplaneand glider to be disconnected during flight. To this end the towingmeans may utilize a draft coupling comprising locking means detachablyinterconnectable with a draft member secured to thetowing cable.However, one of the difficulties encountered in airplane and glidertowing operations arises from the fact that the glider may not travel inthe same plane as the towing airplane and, in fact, the towing airplaneand glider may shift from time to time in their planes of travel withrespect to one another. Thus, the towing connection, such as the cableor the like between the airplane and the glider, will not usually bealigned with the direction of travel of the airplane and glider, butsuch interconnecting cable will usually extend angularly with respect tothe direction of travel thereof. n

Since the angle of draft, or disposition of the interconnecting towingcable between the airplane and glider, must `necessarily assume dierentdirections with respect to the direction of travel, difficulty may beencountered in connection with coupling means heretofore used ineffecting release of the draft connection during flight when itisdesired to drop off the glider being towed by the airplane, suchdiiilcultyarising from the fact.

dition.

Another object of this invention is to provide a very simple andeffective draft coupling for the purposes described wherein the couplingelements are so constructed and arranged that the towing they areenabled to withstand high pulling forces without separation of thelocking elements during coupled relation.

Another object of the invention is to provide va draft coupling in whichthe locking jaws andV draft member adapted for interlocking engagementare so designed as to have extended frictional bearing engagement underdraft conditions and yetare so designed as to admit of a camming actionof the draft member with respect to the locking jaws when the latter arereleased from locking condition, whereby the coupling is capable ofwithstanding high pulling forces without separation under draftconditions, and at the same time provides for quick and positive openingof the locking jaws when release of the towing connection is desiredupon unlocking of the locking means.

Another object of the invention is to provide an indicator or signalmeans cooperative with the locking means or the actuating means thereforto visually indicate the locked condition and the unlocked condition ofthe locking means.

With the foregoing. ends in view, the lembodiment of my invention hereindisclosed includes coupling means comprising a draft member and lockingmeans adapted for detachable and interlocking connection therewith,which locking means is secured to supporting means which may comprise ahousing, the draft member having guide means associated therewith andcooperable with said supporting means when the draft stresses are notcritical, are evenly distributed f member and locking means are incoupled relation. The cooperation of the guide means with saidsupporting means is such as to maintain the draft member in xed relationto thelocking means when the same are in this coupled relation, and thiscooperation is such as to cause the surfaces, providing extendedfrictionalk bearing of the draft member with respect to the locking jawsunder draft conditions when the jaws are locked. The respectiveflattened surfaces on the draft member preferably meet at an angle, theapex of which lies intermediate the respective engaging surfaces of thejaws. This configura- ,A tion.

Figure l is a plan View of apparatus embodyingr my invention, certainparts being shown in section and illustrating the draft means andlocking means in coupled relation.

Figure 2 is a view taken at'right angles to the showing of Figure 1. .g

' spring 23 which causes the bell crank 20 normally to engage a stop ora button 24v in its normal positionshown in Figure l. In this positionthe bell crank lever engages and depresses outwardly an indicator pinbiased inwardly by a spring 26, thereby indicating the closed orv.-lockedcondition of the jaws 2 and` 3. The pin 25moves'in`wa`rdly,. asshown in Figure 3, when the bell crank lever 20 is rotated out ofengagement therewith, thereby indicating the unlocked y condition of thelocking jaws 2 and 3 as shown in Figure "3.

Figure 3 is a-view similar toFigure 1 showing:

the locking means in unlocked conditiorn Figure 4 isa transversesectional viewon the line 4 4 of Figure 1, looking in the direction ofthe arrows.

Figure '5 is a transverse sectional view on the line 5-5 of Figure 1,lookingin the direction of the arrows. 1 Y

Now, referring to the drawings for a descriprbeeffected, from either.Inoperation, when the,

tow lineV and draft member are operative to tow a glider or the like,the draft member i5. and

, locking jaws v,2, and 3 -are'in' coupled relation as tion'of theinvention, the vapparatus there shown comprises supporting meansincluding a housing Iwhich may be cylindrical and secured upon the noseof a glider or upon the tail of ari'airlplane. Within the'housing I arepositioned locking means comprising the oppositely acting locking jaws 2and 3, pivotally mounted on a pin or shaft 1I. These jaws when closed,asshown in Figure 1, are adapted to anchor the towing means comprising adraft member 5, taking the form of a towing ring as illustrated, theY'jaws 2 and 3 engaging around the inner portion of said ring 5, whenthe parts are in coupled rela- The draft member 5 has rigidly securedthereto a guide member 6, comprising a Acover plate adapted to t withinthe housing l in' seating engagement with an annular shoulder or seat Y'I providedV therein, adjacent the open end thereof. `This member Bserves.when sopositioned,

as a'cover, for the housing I,` preventing water or ice from gettingtherein to interferel with the operation of .the lockingmeans,v and alsoserves e lto'position the draft member 5 in fixed relation fVtothe'locking means, comprising thejaw'members 2 and 3, when the draftmember is in coupled` relation to said locking jaws.

The jaws or latches 2 and 3 are provided with leverlextensions 2a and3a`respectively to whichV the toggle` links 8 and 9 are respectivelypivoted as at I0 and II respectively.' The opposite ends of togglelinksVil kand 9 are pivoted to a connecting pin I2, which has journalled ateither end thereof'the bearing' members I3 and I4, which Aare positionedfor'sliding movement in guideseIS and I6 respectively'secured toopposite sides of the cylindrical housing I and extending longitudinallythereof in the direction of application fof the draft force. Links`I1jand I8are pivotecl shown in Figurel, the jaws` 2 and 3 engagingaround the ring 5," and the toggle links 8 and 9 Vare in alignedposition locking the jaws 2 and 3 closed, as lshown in Figure1preventing said jaws 2 and 3 ,from'releasing the ring 5. The tow linestresses are transmitted from the jaws 2 and 3 through the mountingpivot 4 directly into the Vhousing Ijto'be 1distributed into theaircraft framework. Y

. VWhen the pilot desires to release the tow line he pulls on the cable22 attached to bell crank lever 20,, causing the same to be moved in a'clockwise direction, having yreference to Figures 2 and 3, to'move thelink I8, 'toggle links 8 and 9. `and jaws 2 and 3,4 t'o theirvrespective positions, shown in` Figure 3, the jaws 2 and 3 being causedto'openfandrelease' the towing ring '5 upon the 4rearwardmovementfof'the linkage as ju'st described. The guide member B integral.with the Ltow ring'5 ensures that the tow ring 5 will move in apathfree from locking cooperation with'the jaws 2 and 3 under acondition of draft exerted l upon the tow ring 5 during the uncouplingop- 1 eration after the locking jaws 2 and 3 have been opened,4 asindicated in Figure 3,. because of the cooperation of the guide memberli'withl housing VI preventing the tow ring 5 from remaining or becomingengaged with either of the Jaws 2 or 3 during uncoupling. l

In the event that the direction of pull on the tow ring 5-is atvan-arigle Ato the longitudinal axis of the housing I',`thel guidemember 6 serves, during' the unc'oupling operation when the locking jaws2 and 3 are open, asa hinge point in cojoperationl with the housing Ito` cause the tow ring 5 to be ypulled in a pathvfree from lockingengagement with the jaws 2 and 3 in the manto the 'longitudinal axis ofthe housing I. If it to the connecting member` I2 and at theiroppomountedl on. a pin'or shaft 2| 'secured to the housing I. The otherarm of the bell crank levery 1 20 is adaptedto Ybe connected toalrelease cable Y reference to 'Figures 1 and 3, by Vmeans of a siteends these links are pivoted, as at I9, tol one A arm *of a bell cranklever 20 which is pivotally were not for the provision of the integralguide member 6, the towring 5 would tend to remain engaged with theportion 2b of the ,locking jaw 2 during the uncoupling condition justdescribed, due to the angular direction of draft pull on the tow ring 5Vwith respect to the longitudinalaxis ofl the V housing I, even thoughthe jaws 2 and 3 were in unlocked condition as indicated in Fig- 1 ure3, and under such circumstance of the tow ring remaining in engagementwith the portion 2b of the jaw 2 (or the similar curved surface of thejaw 3), the desirable immediate separation of the tow ring 5 from thejaws 2 and 3 when the latter are in unlocked condition would beprevented. Thus, it will be apparent that the cooperation of the guidemember 6 with the housing i will obviate any such condition of the draftmember 5 remaining in locking engagement/with either of the jaws 2 or 3during the uncoupling operation and the guide member 6 ensures immediaterelease of the parts under draft conditions as soon as the jaws 2 and 3are placed in open or unlocked condition indicated by Figure 3.

It will be apparent also that in the coupled relation of the draftmember 5 and the locking jaws 2 and 3, indicated by Figure 1, thecooperation of the guide member 6 with the housing I maintains the towring 5 in predetermined fixed relation with respect to the jaws 2 and 3during the existence of such coupled relation. Thus, the tow ring 5 isprevented from being pulled more against one than the other of the jaws2 and 3 when the direction of draft exerted upon the towing member 5durihg the towing operation is angular to the longitudinal axis of thehousing I. Since, in the construction illustrated, the draft member 5 iscaused to remain in fixed relation to the jaws 2 and 3 when the partsare in coupled relation, the towing@ stresses are evenly distributedupon said jaws 2 and 3.

Moreover, the inner ring engaging surfaces 2b and 3b of the jaws 2 and 3are flattened and the towing ring 5 is provided with correspondinglyflattened surfaces 5a and 5b respectively engaging the flattenedsurfaces 2b and 3b when the parts are in coupled relation, therebyproviding extended frictional bearing area between the towing ring 5 andthe jaws 2 and 3 under draft conditions. This enables the towingconnection, when the draft member 5 and jaws 2 and 3 are in coupledrelation of Figure 1, to withstand greater pulling forces withoutcausing separation of the jaws 2 and 3 when they are in their lockedclosed position of Figure 1. Nevertheless, the flattened surfaces 5a and5b on the towing ring 5 meet at an angle, the apex 5c of which liesintermediate, or on the line of separation between the meeting edges ofthe jaws 2 and 3 when the f parts are in the coupled relation ofFigure 1. Consequently, although the provision of extended frictionalbearing surfaces on the towing ring 5 and jaws 2 and 3 enables the draftcoupling to withstand greater pulling forces vthan would otherwise bethe case under draft conditions, the

Having thus described my invention, what I claim as new and desire .tosecure by Letters Patent is:

1. Means of the class described, in combination, a draft member, ahousing having an opening for receiving the draft member, locking meansassociated therewith and positioned therein and cooperable with saiddraft member for detachably securing the same with respect to saidhousing, and a guide member rigid with said draft member and cooperablewith said housing for causing the draft member to move under draft in apredetermined relation to the locking means upon unlocking of thelatter, whereby the draft member will be drawn free of the looking meansin the uncoupling operation regardless of the direction of the draftpull, said housing having a shoulder providing a seat adjacent saidopening and the guide member comprising a coverplate engaging said seatand closing said hous-` ing when seated.

2. In coupling means of the class described, in combination, a pair ofoppositely acting' locking jaws pivoted on a common axis, and means foractuating said jaws to lock and unlock the same, said actuating meanscomprising a pair of toggle links respectively pivoted to said jaws, l aconnecting pin, said toggle links being pivotally connected thereto,fixed guides cooperable with the opposite ends of said pin, and meansfor move ing the connecting pin in said guides to bring the toggle linksinto and out of alignment, said l biased pin normally in the path ofmovement of a portion of the actuating means, said pin being movablethereby when engaged therewith.

4. In coupling means of the class described, in combination, a draftmember and a pair of oppositely acting locking jaws cooperable therewithfor detachable connection thereto, said jaws engaging around said memberwhen in coupled relation therewith, the engaging portions of said jawsand said draft member having fiat engaging surfaces providing extendedfrictional bearing under draft condition when the jaws are locked, therespective jaw engaging surfaces of said member meeting at an angle, theapex of which lies intermediate the respective engagin"`r-

